Delay arming device for projectile fuses



Feb. 13, 1951 J. F. MccAsLlN 2,541,082

DELAY ARMING DEVICE FOR PROJECTILE FUSES Filed Aug. 2l, 1945 3Sheets-Sheet 2 James FT McEaaln mi afm# lum a Feb- 135 1951 .1. F.MCcAsLlN 2541082' DELAY ARMING DEVICE FOR PROJECTILE FUsEs Filed Aug.21, 1945 s shees-sheet 3 'lll/1111111111 Jamej.' Mclalin DELAY ARMINGSPATENT oFF DEVICE FOR PROJ ECTILE 2,541,082 IC E FUSES James F.McCaslin, Cleveland, Ohio Application April 21, 1945, Serial No. 589,683

, Y 1I) Claims.

(Granted under the act ofMarch 3, 1883, as

amended April 30, 1928; 370 0. G. 757) The invention described hereinmay be manufactured and used by or for the Government for governmentalpurposes without the payment to me of any royalty thereon. n Thisinvention'relate's, to an improved delay iarming device for use withprojectile fuzes of the rotating type and whiclrfunctions to retain afuze, with which it is associated, in a disarmed or safe condition untila projectile, in which the fuze is contained, has traveled apredetermined distance in its flight.

More particularly; the present invention relates to a safety attachmentfor use with the M48, and M51v series fuzes, to vprovide additionalsafety means for delaying the arming of' thefuze to insure a minimumtravel of the projectile in flight prior to the arming of the fuze, andwhich is suicient so that the projectilewill bebeyond a zone where thegun-'crew couldrbe endangered by the detonation of the projectile, whenthe device permits arming of the-fuze. Specifically, the inventioncomprises a centrifu- .gally operated gear train the operation of whichis regulated for arming the fuze at a predeter- ,mined point beyond themuzzle of the Weapon by .releasing a conventional safe-ty element of thefuze. Y

Still a further object of the invention is to provide a device Vof theaforedescribed character capable of beingL readily applied to the typesof fuzes, heretofore mentioned, without. modification ,of theconventional partsof the fuze and by only slight modifications of thefuze housing, by so larranging the parts of the device that they willprincipally occupy an otherwise unused space in thghousing. i 1

, Other objectsand advantages of the invention will hereinafter becomemore fully apparent from the following description of the drawings,which lillustrate a preferred embodiment thereof,l and wherein: i v,

' `Figure 1 isa cross sectional view through a part of a 'M48A2 fuzehousing and showing the delayiarming device, in top plan, disposedtherein and its initial position; i Figure, 2 is a fragmentary viewsimilar to Figure 1` and showing the device in an intermediate position;

Figure 3 is a View similar to Figure 2 showing the device in its final,released position; and

Figures 4, 5,I and Gare longitudinal sectional views to an enlargedscale, taken substantially along vthe planes of" the lines 4 -7-4, 5 5,and

'6e-Q6, respectively, of Figi. Y

Referringmore particularly to the drawings wherein like referencecharacters designate like 4or'corresponding parts throughout the severalingof a portion of the M48A2 fuze and which ineludes an inner portion,support or core 1 which 'isprovded Vwitlrx substantiallyradiallyidisposed we. @thigh @eternamente s biased inwardly by a springI0 and into obstructing' relationship to a sleeve Il. Core 1 isreciprocally mounted lengthwise of housing 6 and relatively to thesleeve l I. A bore I 2 in core 1 accommodates the sleeve II when core 1moves forward relatively to housing 6. Core 1 is normally spring biasedrearwardly by an expansion spring I3. The sleeve II is connected to afiring pin I 4, which iS radially oiiset from the sleeve I I and fromthe axis of the housing 6, and which is in alignment with a primer andpowder train I5, contained in core 1, and which has a flash passage `I6leading to a booster, not shown, disposed behind the core I and which isadapted to be mounted in the nose of a projectile. The parts previouslydescribed and the operation of which will be briefly described, form nopart of the present invention but are conventional in fuzes of theaforementioned types.

Briefly, a detonator, not shown, disposed forwardly of the housing 6,may be exploded upon the impact of a projectile, containing the fuze,with its target, and the blast therefrom will pass through the sleeve II and bore I2 to immediately detonate the booster charge when the fuzeis set for superquick action. The fuze can also be set for delay actionby obstructing the passage `for the flash, from the detonator containedin the nose, forward of the sleeve II. When thus arranged, and assuming"that the plungers 9 have been set back by centrifugal force, uponimpact with a target, core 1 is moved forward, relatively to housing 6,to cause firing pin I4 to strike the primer of powder train I5 whichproduces a flash through passage I6 for setting off the booster andbursting charge, not shown, after a short delay, all of which operationis conventional in fuzes of the aforementioned types. p

The delay arming device, comprising the inf vention, and designatedgenerally l1, is contained for the most part within an annular chamber|8 which is a conventional part of the fuze housing 6 and which islocated for'- wardly of. core 1, Aand in addition, the core 1 isprovided with a forwardly opening well or recess I9 (Fig. 5)constituting a modification thereof and' in which a portion of thedevice I1 is contained. The delay arming device I1 ncludes an elongated,segmental shape-d centrifu- 'gally operated element 20 which iscontained in the well I9 and which is keyed to a shaft 2 I which extendsaxially through said well. The rear end of the shaft 2l is journalled ina recess 22 of the core T, which opens into the bed of the well I9. Theforward end of the shaft 2| extends into the chamber I8 and has keyedthereto a disk 23, a portion of the periphery of views' g designatesgenefanythe part of the hous which is provided with teeth 24, forming agear segment..l A segmental shaped detent or stop 25` is keyed-fte theforward end of the shaft ZI., f

25 are in therecess I8.

v21 in me core 1, and extends forwardly therefrom into the recess I8,and has an escapement wheel 28 keyed thereto and a pinion 29 keyed toits forward end and forwardly of the escapement wheel 28. Escapementwheel 28 and pinion wheel 29 are disposed in the recess o r chamber I3.YAs best seen in Fig. 6, the escapement wheel 28 is disposed behind andin partly overlapping relationship to the disk 23, and the pinion 29 isdisposed in the same plane as the disk 23 and is located so as to meshwith the gear teeth 24, v when the device I1 is in its initial andintermediate positions, as illustrated in Figs. 1 and 2, respectively.

A shaft 30 is seated in a recess 3l of the core 1 and projects forwardlytherefrom into the cham- I ber I8. An escapement or pallet 32 isdisposed in chamber I8 and is swingably mounted on the shaft 30 which isprovided with .a head 33 which Vretains the pallet 32 in engagement withthe 'shaft 30. Pallet 32, as seen in Figs. l-3, is located adjacent theescapement wheel 28 and is provided with pawls 34 for alternatelyengaging the teeth of escapement wheel 28, to regulate the .rotationthereof, in a conventional manner.

, A pin 35 is anchored in the core i and proltr'udes therefrom forwardlyinto the chamber I3. fA lever 38 is provided with an elongated slot 31in Which the pin 35 is loosely received and` by means of which the lever38 is pivotally and slidrably mounted in chamber I8. The lever 33, asseen in Figli, is disposed in the same plane as the stop or detent 25and is provided with a portion 38 which is located in partialoverlapping vrelationship .to the disk 23 and which normally vbearsagainst the arcuate edge of the stop 25, vI fever 36, on the oppositeside of its pivot, is Aprovided with an extension 39.

` Referring to Fig. 6, the core 1 is provided with Aa bore having arestricted rear end 49, which opens .into one of thebores S at its rearend, as `seen in Fig. 4, and an enlarged forward end 4! having aninternally threaded forward portion 42 which opens forwardly into thechamber I3. A bushing 43 is disposed in threaded engagement ywith theportion 42 Vand is provided. with a bore ,of the same diameter-as thebore portion 43 and which is in alignment therewith, for receiving asetback pin 44 which is reciprocally mountedin the bore portion 44 andthe bushing 43. A collar 45 is suitably fixed to the pin 44 and isreciproi cally disposed in the bore portion 4I. A helical spring 48 iscarried by the pin 44 and is contained in the bore portion 4|, betweenthe bed lthereof and the collar 45, for urging the pin 44 forwardly andto its position of Fig. 4; in which position the forward end of the pin44 protrudes into the chamber I8 and forms a stop against which thelever end 39 bears to prevent counterclockwise swinging movement of thelever 36 as seen in Figs. 1-3.

With the pin 44 thus disposed, as seen in Fig. 4, its rear end isdisposed in the rear end of the bore portion 43 adjacent one of theradial bores 8 and slightly behind or outwardly of the plunger 9 whichis disposed therein, for a purpose which will hereinafter be described.

A torsional spring 41 is located in the chamber I8 and is anchored totwo spaced pins 48 which project from the housing 1 forwardly intochamber I8, as clearly illustrated in Figs. 1-3, and is provided with afree end which bears against the terminal of the lever end 39 and whichis biased in a clockwise direction 'for urging the lever portion 39against the setback pin 44 or in a counterclockwise direction.

As seen in dotted lines in Figs. l, 2, and 3, a

Vstop pin 49 projects upwardly from the bed of the well `I9 and isdisposed to be engaged by a portion of the member 2U, when in itsposition of Figs. 1 and 2 to prevent back Winding of the gear trainbeyond its starting position. A weighted arm 50 is swingably mounted inchamber I8 on a headed pin 5I which is anchored in core 1. A torsionalspring 52 is anchored in a split pin-53 which projects into the chamberI8 fromthe core 1. Spring 52 bears against arm 50 for biasing said armagainst a portion of the pallet 32 to resist rocking movement of thepallet to thereby prevent inadvertent movement of the gear train. Thearm 50 is centrifugally swung out of engagement with the pallet 32, whenthe fuze is rotated in'flight, to release the pallet and gear train fornormal operation.

The parts of the device I1 which are contained in the chamber I8 areretained in place by means of a cover shown in dotted lines at 54, inFigs. 4 and 5.

Assuming the parts of the device I1 and of the fuze to be in theirinitial positions, as shown in Figs. 1 and 4, when a projectile, notshown, containing the parts is red from a weapon, the initialacceleration of the projectile will cause the pin 44 to be set lbackagainst the thrust of its spring 48. This rearward movement of the pin44 will cause the rear end thereof to move into the bore 8, into Whichthe bore 40 opens, outwardly or behind the plunger 9 thereof, to form astop to prevent radial outward retraction of said plunger 9 to aposition where it will release the stem II. Likewise, the rearwardmovement of the pin 44 will cause the forward end thereof to move out ofthe chamber I8 and out of engagement with Ythe lever end 39. The lever36 thus being released at its end 39 will slide in a directionsubstantially radially outward of the cham,- ber I8 to the extend of itsmovement as permitted by the slot 31, so that said lever will move fromits position of Fig. 1 to its position of Fig. 2. This movement isprimarily produced by the free end of the spring 41 bearing `against theterminal of the lever portion 39, but is also partially caused by thecentrifugal force resulting from the rotation of the fuze. Therotationof the fuze will cause the segmental weighted element 28 to begin torevolve Vin a clockwise direction, as seen in Figs. 1 to 3, from itsposition of Figs. 1 and 2. The disk 23 and stop 25, being rotativelyconnected to the member 20, will be rotated therewith so that said stop25 is rotated relatively to the concave edge of the leverportion 38.Likewise, the rotation of the parts 20, 23, and 25 are regulated by theescapement wheel 28 and pallet .32, due to the fact that the gear teeth24 are in mesh with the pinion 29 which is rotatably con- .nected to theescapement wheel 28. `As the stop 25 approaches its position of Fig. 3,the rgear teeth-24 move-out of mesh with the pinion 29 to permit afinal, free movement of the parts 20, 23, and 25, and as the trailing,substantially radial edge of the stop 25 clears the terminal of thelever portion 38, said lever end 38 is released and thereby permitted toswing byv centrifugal force in a clockwise direction from its positionof Fig. 2 to its position of Fig. 3. This clockwise 'movement of lever36causes its end 39 to move ont o f obstructing.,relationship to pin 44, andas dceleratdon'of theproiectile has already com,

menced, spring 46 will project the pinl 44 forwardly and back to itsposition of Fig. 4, to release the yplunger 9, which was held thereby,so that said plunger can bey retracted radially outwardly and out ofengagement with the sleeve Il. The other plunger 9 will have beenpreviously moved outwardly by centrifugal force so that the fuze willhave been held in a disarmed condition only by the plunger 9, which wasengaged by the setback pin 44. Therefore, it will be readily apparentthat the device Il regulates the arming of the fuze when set for delayfunctioning. By simple expedient, such as varying the number of teeth24, the length of time and the distance of night required to arm theprojectile fuze can be accurately regulated.

Various modifications and changes are contemplated and may obviously beresorted to without departing from the spirit and scope of the inventionas hereinafter defined by the appended claims, as only a preferredembodiment thereof has been disclosed.

I claim:

l. A delay action arming device for projectile fuzes of the rotatingtype, comprising a setback pin movable, upon acceleration of a fuze inwhich it is contained, into a position to render the fuze safe, arelease lever slidably and pivotally mounted relatively to the setbackpin, a centrifugally actuated detent against which the lever bears, saidpin being setback upon acceleration out of engagement with the leverwhereby the lever is released for sliding movement into a position toprevent return of the setback pin, and said detent being movable byrotation of the fuze, to a position to disengage the lever, whereby thelever is centrifugally swung to a position in unobstructing relationshipto the setback pin so that upon deceleration, said pin is free to moveto a position to arm the fuze.

2. A delay action arming device as in claim l, and escapement means forregulating the movement of the detent to a lever releasing position.

3. A delay action fuze as in claim 1, and a torsional spring for urgingsaid lever into an obstructing position relatively to the setback pin.

4. In a fuze for projectiles of the rotating type having a firing meanssecured thereto, a core slidable in said fuze relative to said ringmeans, centrifugal means in said core engaging said ring means to holdthe same and said core immovable relative to each other and a delayarming device for the fuZe, comprising a setback pin movable uponacceleration of the fuze into contact with the centrifugal means to holdthe Same inactive against centrifugal force thereby rendering the fuzesafe, a pivotally mounted release lever normally engaging the setbackpin and centrifugally movable when released by setback of said pin, intoan obstructing position relatively to the pin, and a centrifugallyactuated detent, against which the lever bears, movable by centrifugalforce of the fuze in flight, for releasing the lever for movement to aposition in unobstructing relationship to the setback pin, and springmeans cooperating with said setback pin and effective to move the sameupon deceleration of the fuze in the direction of its flight, away fromthe centrifugal means to release said ring means and said core forrelative movement to each other, thereby arming the fuze.

5. A delay arming device as in claim 4, and escapement means forcontrolling the centrifugally impelled movement of the detent.

6. A delay arming device as in claim 4, said Number release lever beingmounted for sliding and pivoting movement.

'7. A delay arming device as in claim 4, said release lever beingmounted for sliding and pivoting movement, and a torsional springbearing against the release lever for urging it into an obstructingposition relatively to the setback pin.

8. A delay arming device as in claim 4, a gear segment rotatable withthe detent, a pinion in mesh with the gear segment, an escapement wheelrotatable with the pinion, and a pallet for governing the step by steprotation of the escapement Wheel.

9. In a delayed action arming device for a projectile fuse of therotating, centrifugallyarmed type, a support adapted for attachment witha projectile and rotatable therewith about a longitudinal axis, anarming plunger iitting a radial bore in said support and slidable, inresponse to centrifugal force, from a safe position t0 a fuZe-armingposition, a setback pin slidable in said support in response toacceleration, from a first position to a second position in the path ofsaid plunger and, when in second position, preventing movement of saidplunger to fuZe-arming position, means urging said pin into firstposition, a segmental-shaped stop pivoted in said support,centrifugally-operated means connected with said stop to pivot the same,escapement means carried by said support and normally connected tocontrol the rate of rotation of said stop, a lever slidably andpivotally mounted in said support, spring means urging said lever into aposition with respective ends in contact with said stop and pin, saidpin when moved to second position, releasing one end of said lever formovement into the path of said pin to hold the same in second position,said stop when rotated to predetermined position under control of saidescapement, releasing the other end of said lever to permit movementthereof out of said obstructing relation to free said pin and permitarming of said fuze.

10. In a delay action arming device for projectile fuzes of the rotatingtype, a plunger movable in response to centrifugal force from a safeposition to a fuze-arming position, a lever slidably and pivotallymounted for movement into rst, second and third consecutive positions,means urging said lever into said positions, consecutively, a pin and amovable stop normally engaging opposite ends of said lever,respectively, to hold the same in rst position, said pin being movable,in response to linear acceleration, to release said lever for movementto second position and simultaneously to obstruct movement of saidplunger to fuze-arming position, said lever in second positionobstructing return movement of said pin, and centrifugally-operatedtime-controlled means operable to move said stop out of contact Withsaid lever to permit movement of said lever to third position, saidlever in third position again releasing said pin for movement to freesaid plunger.

JAMES F. MCGASLIN.

REFERENCES CITED UNITED STATES PATENTS Name Date 1,496,271 Junghans June3, 1924 1,523,073 Junghans l Jan. 13, 1925 1,665,666 Junghans Apr. 10,1925

